Table 5 Variables and their levels based on the RSM-CCD method.
Factor | Name | Units | Minimum | Maximum | Coded low | Coded high | Mean | Std. Dev. |
|---|---|---|---|---|---|---|---|---|
X1 | Qc | (l/h) | 1.50 | 5.50 | −1 ↔ 1.00 | + 1 ↔ 5.00 | 3.56 | 1.03 |
X2 | Qd | (l/h) | 3.25 | 6.25 | −1 ↔ 1.00 | + 1 ↔ 5.00 | 4.71 | 0.69 |
X3 | Af | (cm/s) | 0.70 | 1.30 | −1 ↔ 0.70 | + 1 ↔ 1.30 | 1.08 | 0.13 |
X4 | σ | (mN/m) | 9.95 | 36.00 | −1 ↔ 9.00 | + 1 ↔ 36.00 | 20.51 | 9.82 |
X5 | TBP | (%) | 0.00 | 30.00 | −1 ↔ 0.00 | + 1 ↔ 30.00 | 12.50 | 11.53 |
